It is evident that there exists potential to add value to rainwater via affirmative design that enables the rain to serve as an ecologic, aesthetic, biophilic, and operational resource in the built environment. When all of these dimensions are fused into a multipurpose design the rainwater can realize its full potential.
2002 Urban Fellow
Research Topic: Water Resources
Faculty Advisor: Gaboury Benoit
Urban Rainwater: From Pollution Source to Resource Via Value-Added Design
The design of stormwater infrastructure and management systems in the United States has been largely reactionary and motivated by avoiding negative storm-related events in urbanized areas. More specifically, as densely developing areas pave roads and erect structures the otherwise pervious ground becomes virtually sealed. During rain events this results in the accumulation of significant volumes of rainwater in an environment occupied principally by humans. To resolve this problem, infrastructure has been developed and implemented to quickly remove this water from the streets and either discharge it into a designated outfall water body or treat it at a chosen wastewater treatment plant. As stormwater flows through the built environment it accumulates various constituents (auto fluids, sediments, metals, temperature) that are foreign and detrimental to the ecological viability of its outfall water body. A separate storm/sewer system is designed to directly discharge this runoff into a designated outfall water body. A combined system is designed to combine sewer and rainwater in the same pipe and treat the combined volume at a wastewater treatment plant. During significant storm events, however, treatment facilities are unable to accommodate the significant volume of rainwater and the system is designed to direct the combined waste to a selected outfall water body (“Combined Sewer Overflow” or “CSO”). As cities grow, so do the ratio of impervious to pervious surfaces and subsequently the frequency of CSOs. In reaction to this problem, municipalities have allocated significant sums of money towards the removal of stormwater from the combined system. In addition to several natural management strategies such as tree planting and downspout disconnection, the City of Portland, Oregon is installing new underground pipes to intercept CSOs from existing combined systems and divert them to upgraded treatment facilities as part of its 20 year, $1 billion CSO reduction program. New Haven, Connecticut currently plans to separate the currently combined system in Fair Haven at the cost of around $15 million (Piscotelli, personal communication). Underground structural management strategies are effective in reducing runoff pollution yet are extremely expensive and add no value to rainwater as a resource. The design of this type 4 of system merely directs the water elsewhere to insure that the polluted water will undergo an energy intensive treatment process prior to discharge. Further contributing the shortcomings of this design is that the infrastructure is located underground rendering the rainwater virtually invisible to the city or building occupant. As a result, perceptions of rainwater are limited to the rain falling in the air and the runoff flowing to the nearest storm drain. This promotes the discernment that rain has no place in cities and that the best thing to do is remove it from the human experience as soon as possible. As a result, little creativity or effort beyond simplified, underground mega-infrastructure is given to rainwater management design. This paper seeks to reveal the potential to add value to rainwater as a viable resource in urban areas via design that positively engages both humans and nature in the built environment. It examines rainwater design in the context of the LEED Green Building Rating System, biophilia, three commercial rainwater projects, and three residential applications in an effort to show what may result from properly designed, awareness-promoting demonstration projects.